/*
    * Copyright (C) 2007 The Guava Authors
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  package org.apache.hadoop.hbase.io;
  
  import java.io.FilterInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Preconditions.checkNotNull;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  /**
   * Copied from guava source code v15 (LimitedInputStream)
   * Guava deprecated LimitInputStream in v14 and removed it in v15. Copying this class here
   * allows to be compatible with guava 11 to 15+.
   */
  @InterfaceAudience.Private
  public final class LimitInputStream extends FilterInputStream {
    private long left;
    private long mark = -1;
  
    public LimitInputStream(InputStream in, long limit) {
      super(in);
      checkNotNull(in);
      checkArgument(limit >= 0, "limit must be non-negative");
      left = limit;
    }
  
    @Override
    public int available() throws IOException {
      return (int) Math.min(in.available(), left);
    }
  
    // it's okay to mark even if mark isn't supported, as reset won't work
    @Override
    public synchronized void mark(int readLimit) {
      in.mark(readLimit);
      mark = left;
    }
  
    @Override
    public int read() throws IOException {
      if (left == 0) {
        return -1;
      }
  
      int result = in.read();
      if (result != -1) {
        --left;
      }
      return result;
    }
  
    @Override
    public int read(byte[] b, int off, int len) throws IOException {
      if (left == 0) {
        return -1;
      }
  
      len = (int) Math.min(len, left);
      int result = in.read(b, off, len);
      if (result != -1) {
        left -= result;
      }
      return result;
    }
  
    @Override
    public synchronized void reset() throws IOException {
      if (!in.markSupported()) {
        throw new IOException("Mark not supported");
      }
      if (mark == -1) {
        throw new IOException("Mark not set");
      }
  
      in.reset();
      left = mark;
    }
  
    @Override
    public long skip(long n) throws IOException {
      n = Math.min(n, left);
     long skipped = in.skip(n);
     left -= skipped;
     return skipped;
   }
 }